The invention relates to a trigger/firing arrangement of a Marx generator including n stage capacitors n being a natural-number greater than 1—the same amount of switches/spark gaps and 2(n−1) charging branches with the spark gaps operating in a self-breakdown mode.
With a uni-polar output voltage, the Marx generator has generally as many spark gaps as it has stage capacitors. In its most simple construction, the spark gaps operate in self-breakdown mode. To each spark gap, except for the output spark gap, two charging branches are connected, one to each of the two connectors of the spark gap. As a result, there are altogether 2(n−1) charging branches associated with an n-stage Marx generator. With a charging voltage U at each of the stage capacitors at the output of the Marx generator, a voltage pulse with a peak value of n*U is obtained at breakdown.
Marx generators which can be triggered in a controlled manner either have three-electrode spark gaps or spark gaps with a trigger pin similar to a spark plug, known also as Trigatron Principle. Such Marx generators are generally operated in single pulse mode. To trigger repetitively operated Marx generators spark gaps are attempted to be operated in accordance with the principles mentioned with regard to minimum wear (see [1]) or to make the triggering operationally secure by optimized trigger generators (see [2]).
Furthermore, laser triggering methods or the use of semi-conductor switches instead of spark gaps are being examined (see[4]). Another trigger method resides in the voltage inversion principle of the LC-Marx generator. In [5], a variant of this principle is described wherein transformers are used for the coupling between the steps. In addition, there are publications concerning the optimizing of the self-breakdown of spark gaps for the non-triggered operation (see [6]).
In spark gaps which can be triggered the trigger electrodes are subjected to high stress because of their exposed locations. Furthermore, the mechanical setup of a spark gap that can be triggered is more complicated than a spark gap without a trigger electrode.
It is the object of the present invention to trigger Marx generators with little wear by an over-voltage breakdown of one or more spark gaps at predetermined points in time particularly with regard to repetitive operations.